Atoms can be seen with the naked eye.
Atoms do not have mass.
Atoms make up every substance around you.​

Answer:

your nervous system C:

Answer:

It would be C.  

(Circulatory)

Explanation:

Breathing starts when you inhale air into your nose or mouth. It travels down the back of your throat and into your windpipe, which is divided into air passages called bronchial tubes. For your lungs to perform their best, these airways need to be open. Knowing that it all starts from the inside is what you should remember.

Answer:

Initial rate of reaction is [tex]2.07\times 10^{-3}M.s^{-1}[/tex].

Explanation:

It is a second order reaction.

Initial rate of reaction = [tex]k[O_{3}]_{0}[NO]_{0}[/tex]   , where k is rate constant, [tex][O_{3}]_{0}[/tex] is the initial concentration of [tex]O_{3}[/tex] and [tex][NO]_{0}[/tex] is the initial concentration of NO.

Here, k = [tex]4.09\times 10^{6}M^{-1}.s^{-1}[/tex], [tex][O_{3}]_{0}=5.84\times 10^{-6}M[/tex] and [tex][NO]_{0}=8.65\times 10^{-5}M[/tex]

So, initial rate of reaction = [tex](4.09\times 10^{6}M^{-1}.s^{-1})\times (5.84\times 10^{-6}M)\times (8.65\times 10^{-5}M)[/tex]

= [tex]2.07\times 10^{-3}M.s^{-1}[/tex]

So, initial rate of reaction is [tex]2.07\times 10^{-3}M.s^{-1}[/tex]

Answer:  0.17 m [tex]CH_3COONH_4[/tex] : Highest freezing point

0.20 m [tex]CoSO_4[/tex]: Second lowest freezing point

0.18 m [tex]MnSO_4[/tex]: Third lowest freezing point

0.42 m ethylene glycol: Lowest freezing point

Explanation:

Depression in freezing point  is a colligative property which depend upon the amount of the solute.

[tex]\Delta T_f=i\times k_f\times m[/tex]

where,

[tex]\Delta T_f[/tex] = change in freezing point

i= vant hoff factor

[tex]k_f[/tex] = freezing point constant

m = molality

a) 0.17 m [tex]CH_3COONH_4[/tex]

For electrolytes undergoing complete dissociation, vant hoff factor is equal to the number of ions it produce. Thus i =2 for [tex]CH_3COONH_4[/tex], thus total concentration will be 0.34 m

b) 0.18 m [tex]MnSO_4[/tex]

For electrolytes undergoing complete dissociation, vant hoff factor is equal to the number of ions it produce. Thus i = 2 for [tex]MnSO_4[/tex], thus total concentration will be 0.36 m

c) 0.20 m [tex]CoSO_4[/tex]

For electrolytes undergoing complete dissociation, vant hoff factor is equal to the number of ions it produce. Thus i = 2 for [tex]CoSO_4[/tex], thus total concentration will be 0.40 m

d) 0.42 m ethylene glycol

For non electrolytes undergoing no dissociation, vant hoff factor is equal to 1 . Thus i = 1 for ethylene glycol, thus concentration will be 0.42 m

The more is the concentration, the highest will be depression in freezing point and thus lowest will be freezing point.

Answer:

The current generated by the human per day = 89.34 Amperes

Explanation:

Given that ;

the human consumes 20.0  mole of O₂ per day

The Food oxidation is given by the reaction :

[tex]O_2 + 4 H^+ + 4 e^- ----> 2H_2O[/tex]

So; the human will produce  20.0 × 4 moles of e⁻

Thus; moles of e⁻ produced  is = 80

Charge on 1  e⁻ = 1.602 × 10⁻¹⁹  C

e⁻ in 1 mole = 6.023 × 10²³

The total charge per day = [tex]\frac{1.602*10^{-19}*6.023*10^{23}*80}{24*60*60}[/tex]

= 89.34 Amperes

Answer:

Naming ionic compounds with transition metals isn't too hard either. They are named like the binary compounds, with the cation first, then the anion with -ide added to it, but you have to take into account the variations of the metal ions.

Explanation:

Answer:

0.15 M

Explanation:

Step 1: Write the neutralization reaction

NaOH + HCl ⇒ NaCl + H₂O

Step 2: Calculate the moles of HCl that reacted

10 mL of 0.15 M HCl was used. The moles of HCl that reacted are:

[tex]0.010L \times \frac{0.15mol}{L} = 1.5 \times 10^{-3} mol[/tex]

Step 3: Calculate the moles of NaOH that reacted

The molar ratio of NaOH to HCl is 1:1. Then, the moles of NaOH that reacted are 1.5 × 10⁻³ moles.

Step 4: Calculate the concentration of NaOH

1.5 × 10⁻³ moles of NaOH are in 10.3 mL of solution. The molarity of NaOH is:

[tex]\frac{1.5 \times 10^{-3} mol}{10.3\times 10^{-3}L} =0.15 M[/tex]

A current of 620 A for 90 seconds produces 5.209 g of aluminum.

The mass of pure aluminum produced in the Hall-Heroult process can be calculated by using Faraday's laws of electrolysis and the molar mass of aluminum. First, we determine the moles of electrons transferred using the given current and time. Then, using the stoichiometry of the reaction where 4 moles of Al are produced per 12 moles of electrons:

Calculate the charge (Q) passed: Q = current (I) x time (t) = 620 A x 90.0 s = 55800 C

Determine the moles of electrons: Moles of e- = Q / Faraday's constant (F) Assuming the Faraday constant is approximately 96500 C/mol, this gives Moles of e- = 55800 C / 96500 C/mol = 0.5784 mol

Calculate the moles of aluminum: Since 3 moles of electrons yield 2 moles of Al, 0.5784 mol of e- will yield (4/12) x 0.5784 mol of Al = 0.1931 mol of Al.

Compute the mass of aluminum produced: Mass of Al = moles of Al x molar mass of Al = 0.1931 mol x 26.98 g/mol = 5.209 g

The mass of pure aluminum produced is therefore 5.209 g, assuming 100% efficiency and no other side reactions.

To find the mass of pure aluminum produced, we calculate the charge passed, find the moles of electrons transferred, determine the moles of aluminum from the moles of electrons, and use the molar mass of aluminum to find that approximately 5.20 grams of aluminum is produced.

To calculate the mass of pure aluminum produced in the Hall-Heroult process when 620 A of current is passed through a Hall-Heroult cell for 90.0 seconds, we use Faraday's laws of electrolysis. The reduction of aluminum oxide to aluminum involves the transfer of three moles of electrons per mole of aluminum according to the equation:

Al₂O₃ + 3e⁻ → 2Al + 1.5O₂

Firstly, we calculate the amount of charge passed using the formula Q = It, where Q is the charge in coulombs, I is the current in amperes, and t is time in seconds. Then, using Faraday's constant (96485 C/mol), we determine the moles of electrons transferred. Since we need 3 moles of electrons to produce 1 mole of aluminum, we find the moles of aluminum formed by dividing the moles of electrons by 3. Finally, we calculate the mass using the molar mass of aluminum (26.98 g/mol).

Q = 620 A * 90.0 s = 55800 C
Moles of electrons = Q/F = 55800 C / 96485 C/mol ≈ 0.5785 mol
Moles of aluminum = Moles of electrons / 3 ≈ 0.1928 mol
Mass of aluminum = Moles of aluminum * Molar mass of Al
Mass of aluminum ≈ 0.1928 mol * 26.98 g/mol ≈ 5.20 g

The mass of pure aluminum produced is approximately 5.20 grams.

Answer:

caffience

Explanation:

Answer: 0.887 g of [tex]MnO_2[/tex] should be added to excess HCl(aq).

Explanation:

According to ideal gas equation:

[tex]PV=nRT[/tex]

P = pressure of gas = 805 torr = 1.06 atm  (760torr=1atm)

V = Volume of gas = 235 ml = 0.235 L

n = number of moles = ?

R = gas constant =[tex]0.0821Latm/Kmol[/tex]

T =temperature =[tex]25^0C=(25+273)K=298K[/tex]

[tex]n=\frac{PV}{RT}[/tex]

[tex]n=\frac{1.06atm\times 0.235L}{0.0820 L atm/K mol\times 298K}=0.0102moles[/tex]

[tex]MnO_2(s)+4HCl(aq)\rightarrow MnCl_2(aq)+2H_2O(l)+Cl_2(g)[/tex]

According to stoichiometry:

1 mole of chlorine is produced by = 1 mole of [tex]MnO_2[/tex]

Thus 0.0102 moles of chlorine is produced by = [tex]\frac{1}{1}\times 0.0102=0.0102[/tex] moles of [tex]MnO_2[/tex]

Mass of [tex]MnO_2[/tex] =[tex]moles\times {\text {Molar mass}}=0.0102mol\times 87g/mol=0.887g[/tex]

0.887 g of [tex]MnO_2[/tex] should be added to excess HCl(aq).

The enthalpy change when 1.6 kg of methane gas is heated from a temperature of 280 K to 320 K is 140.6 kJ.

The subject this question pertains to is heat capacity and enthalpy change in the field of Chemistry. Simply put, when the temperature of an amount of substance changes, the change in enthalpy (∆H), can be calculated using the formula, ∆H = nCp∆T, where n is the number of moles, Cp is the heat capacity at constant pressure, and ∆T is the change in temperature.

To calculate the answer to your question, we need to convert the mass of methane gas to moles because the molar heat capacity is given. The molar mass of methane (CH4) is approximately 16.04 g/mol. Thus, we have: n (number of moles) = mass (in kg) / molar mass (in kg/mol) = 1.6 kg / 0.01604 kg/mol = 99.75 mol.

The next step is to plug our numbers into the formula: ∆H = nCp∆T = 99.75 mol * 35.31 JK-1mol-1 * (320 K - 280 K) = 140.6 kJ.

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Answer: The new pressure is 7.1 atm

Explanation:

To calculate the final pressure of the system, we use the equation given by Gay-Lussac Law. This law states that pressure of the gas is directly proportional to the temperature of the gas at constant pressure.

Mathematically,

[tex]\frac{P_1}{T_1}=\frac{P_2}{T_2}[/tex]

where,

[tex]P_1\text{ and }T_1[/tex] are the initial pressure and temperature of the gas.

[tex]P_2\text{ and }T_2[/tex] are the final pressure and temperature of the gas.

We are given:

[tex]P_1=6.5atm\\T_1=22^0C=(22+273)K=295K\\P_2=?\\T_2=50^0C=(50+273)K=323K[/tex]

Putting values in above equation, we get:

[tex]\frac{6.5}{295}=\frac{P_2}{323}\\\\P_2=7.1[/tex]

Hence, the new pressure is 7.1 atm

Final answer:

The new pressure in the steel container filled with H₂ gas, after being heated from 22°C to 50°C, is approximately 7.18 atm, calculated using Gay-Lussac's law.

Explanation:

The question deals with the effect of temperature change on the pressure of a gas within a steel container. According to Gay-Lussac's law, the pressure of a gas is directly proportional to its absolute temperature when the volume and the amount of gas are held constant. This situation can be represented mathematically as P1/T1 = P2/T2, where P1 and T1 are the initial pressure and temperature, and P2 and T2 are the final pressure and temperature, respectively.

To find the new pressure in the container when the temperature is increased from 22°C to 50°C, we first need to convert these temperatures to Kelvin by adding 273. Thus, T1 = 22 + 273 = 295 K and T2 = 50 + 273 = 323 K. Substituting the initial conditions into the equation along with T2, we can solve for P2. Using P1 = 6.5 atm and rearranging the formula gives us P2 = P1 * (T2/T1) = 6.5 * (323/295) ≈ 7.18 atm. Therefore, the new pressure in the container after heating is approximately 7.18 atm.

Answer:

DMF is an aprotic polar solvent.

hence CN acts as a strong nucleophile in DMF to give SN2 reaction with the reactant resulting into inversion of  configuration at stereo centers.

Explanation:

check the attached file for little explanation(diagram)

The correct answer is that the major product of reacting the given molecule with sodium cyanide in di-methyl formamide (DMF) would be the nitrile compound formed by the nucleophilic addition of the cyanide ion to the carbonyl carbon of the molecule.

To understand the reaction, let's consider the mechanism step by step:

 1. The carbonyl group in the given molecule contains a carbon atom that is electrophilic due to the partial positive charge on it, resulting from the electron-withdrawing effect of the oxygen atom.

 2. Sodium cyanide (NaCN) dissociates in the polar aprotic solvent DMF to give free cyanide ions (CN^-). The cyanide ion is a good nucleophile because of the negative charge on the carbon atom.

 3. The cyanide ion attacks the electrophilic carbonyl carbon, leading to the formation of a tetrahedral intermediate.

 4. The intermediate then undergoes elimination of a hydroxide ion (OH^-), which is a good leaving group, to form the nitrile.

 5. The final product is the nitrile compound, where the carbonyl oxygen has been replaced by the cyanide group.

 The reaction can be represented as follows:

  In this reaction, R and R' represent the alkyl or aryl groups attached to the carbonyl carbon. The product is a nitrile, which has a carbon triple-bonded to a nitrogen (C}\equiv\text{N}), and this is the major product of the reaction under the given conditions.

 It is important to note that the reaction conditions, such as the use of a polar aprotic solvent like DMF, favor the formation of the nitrile by stabilizing the transition state and the intermediate, and by not protonating the cyanide ion, which would reduce its nucleophilicity.

Answer:

Kw= = [H3O+][OH-] = [H+][OH-].

Explanation:

In chemistry, the term 'equilibrium'' is a period or time in which the rate at which the product is been produced or generated is equal to the quantity of the reactants reacting. In order way, we can say the equilibrium is when forward Reaction is equal to the backward Reactions.

The general equilibrium expression for the self-ionization of water is given below;

Kw = [H3O+][OH-] = [H+][OH-].

The kw is now equal to 1.001x10-14 at 25°C. Kw which is the equilibrium constant is also refer to as the dissociation constant of water.

Answer:

Chloroethane is denser and has a higher boiling point

Explanation:

The density of a gas depends directly on the molar mass of the gas. This means that as the molar mass increases, density increases and vice versa.

Having said that, we can easily see that the molar mass of chloroethane (64.51 g/mol) is greater than the molar mass of ethane (30.07 g/mol). Hence we expect that chloroethane is denser than ethane as established above.

In the absence of other strong intermolecular forces, the higher the molecular mass of a substance the greater its boiling point. Thus the boiling point of chloroethane is higher than that of Ethane since they both have weak Van der Waals forces holding their molecules together in the gaseous state.

Answer:

This reaction is favorable, and is likely regulated.

Explanation:

The equation to calculate delta G (dG) of a reaction is dG = dGo' + RTln [initial P]/[initial R]. You could use just dG = RTln [initial P]/[initial R] if (and that's a big IF) dGo' is zero, meaning that the reaction is at equilibrium when we have equal amounts of [P] and [R] (which is rarely the case). What really matters is the ratio of Q ([initial P]/[initial R]) to Keq ([P at equilibrium]/[R at equilibrium]), meaning how far off are we from equilibrium.

If Q=Keq, we are already at equilibrium (EQ).

If Q<Keq, we are not yet at EQ, having relatively more [R], or less [P] than under EQ conditions. This means the reaction will move forward to produce more P until EQ is achieved (dG is therefore NEGATIVE).

If Q>Keq, we are also off EQ, but we have relatively more [P], or less [R] than under EQ conditions. This means the reaction will move backwards to produce more R until EQ conditions are achieved (dG is therefore POSITIVE).

Try to understand these equations below (they say what I tried to describe in words)

dGo' = -RTlnKeq (under "standard conditions", i.e. we try to figure out how a reaction "behaves" if we start out with the same molar concentrations of R and P)

dG = dGo' + RTlnQ Q=[initial P]/[initial R]   or

dG = -RTlnKeq + RTlnQ or

dG = RTlnQ - RTlnKeq   or

dG = RTln Q/Keq

Answer:

The correct answer is (c) 1 × 10⁻⁹ M

Explanation:

Hydroxide ion = OH⁻

Hydrogen ion = H⁺

The autoionization equilibrium of water at 25ºC has a water constant Kw which is expressed as follows:

Kw = [H⁺] x [OH⁻]= 1 x 10⁻¹⁴

If we know the concentration of hydroxide ion ([OH⁻]) we can calculate the hydrogen ion concentration ([H⁺]) as follows:

[H⁺] = Kw/[OH⁻]= (1 x 10⁻¹⁴)/1 x 10⁻⁵ M= 1 x 10⁻⁹ M

The hydrogen ion concentration of a solution with a hydroxide ion concentration of 1 × 10-5 M is 1 × 10-9 M.

In chemistry, the product of the concentration of hydrogen ions [H+] and the concentration of hydroxide ions [OH-] in a solution always equals 1 × 10–14 M² at a temperature of 25°C (this is known as the ion product of water).

Since the concentration of hydroxide ions [OH-] in your solution is given as 1 × 10-5 M, you can calculate the concentration of hydrogen ions [H+] by dividing the ion product of water, 1 × 10-14 M², by the concentration of hydroxide ions [OH-]. Therefore, the hydrogen ion concentration [H+] in your solution would be 1 × 10-14 M² / 1 × 10-5 M = 1 × 10-9 M.

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Answer:

Electrolysis of either the molten or aqueous salt will produce solid iron.

Explanation:

Iron (II) iodide has a relatively low melting point. Electrolysis of the molten salt will probably produce solid metallic iron and liquid I2 as well as iodine vapor. The temperature need not be high enough to cause Fe to melt.

so Electrolysis of either the molten or aqueous salt will produce solid iron.

When The Electrolysis of either the molten or aqueous salt will produce solid iron. So The temperature need not be high enough to cause Fe to melt.

When Iron (II) iodide has a moderately low melting point. Electrolysis of the molten salt will probably construct solid metallic iron and liquid I2 as well as iodine vapor. The temperature requirement not be high enough to cause Fe to melt.

Therefore, The Electrolysis of either the molten or aqueous salt will produce solid iron.

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Answer:

A. 145.2 g NH3

B. 0.76 g H2

C. 1.41 x 10^22 molecules NH3

Explanation:

A. 1 mol N2    -> 2 mol NH3

   4.27 mol N2 -> x

x= (4.27 mol N2 * 2 mol NH3)/1 mol N2     x= 8.54 mol NH3

1 mol N2       -> 17 g

8.54 mol N2 -> x        x= 145.2 g NH3

B.

2 g H2  -> 34 g NH3

         x   -> 13.01 g NH3

x= 0.76 g H2

C.

2 g  H2      -> 34 g NH3

0.0235 g H2 -> x

x=   0.39 g NH3

0.39 g NH3 (1 mol NH3/17 g NH3)(6.023 x 10^23 molecules/1 mol NH3) =

1.41 x 10^22 molecules NH3

Answer:

See explaination

Explanation:

To calculate the second law of efficiency, temperatures here should be in Kelvin → K = ºC + 273.15 or Rankin = 460 + ºF. 2. Second Law Efficiency Second Law efficiency is a measure of how much of the theoretical maximum (Carnot) you achieve, or in other words, a comparison of the system's thermal efficiency to the maximum possible efficiency.

See attachment for the step by step solution of the given problem.

To solve this problem, we'll follow these steps:

a. Determine the entropy change per unit mass, (s2 - s0): The entropy change per unit mass can be calculated using the following equation:

[tex]\[ \Delta s = c_p \ln\left(\frac{T_2}{T_1}\right) - R \ln\left(\frac{P_2}{P_1}\right) \][/tex]

where:

- [tex]\( c_p \)[/tex] is the specific heat at constant pressure,

- [tex]\( R \)[/tex]is the gas constant,

- [tex]\( T_1 \) and \( T_2 \)[/tex] are the initial and final temperatures in Kelvin,

-[tex]\( P_1 \) and \( P_2 \)[/tex]are the initial and final pressures.

Given values:

- [tex]\( c_p = 1.009 \) kJ/kg·K[/tex]

- [tex]\( R = 0.287 \) kPa·m³/kg·K[/tex]

-[tex]\( T_1 = 28 + 273.15 \) K[/tex]

- [tex]\( T_2 = 231 + 273.15 \) K[/tex]

- [tex]\( P_1 = 137 \) kPa[/tex]

-[tex]\( P_2 = 830 \) kPa[/tex]

Substitute the values into the entropy change equation to calculate[tex]\( \Delta s \) per unit mass.[/tex]

[tex]\[ \Delta s = 1.009 \ln\left(\frac{231 + 273.15}{28 + 273.15}\right) - 0.287 \ln\left(\frac{830}{137}\right) \][/tex]

b. Determine the volume change per unit mass, (v2 – v0): The volume change per unit mass can be calculated using the equation:

[tex]\[ \Delta v = R \ln\left(\frac{V_2}{V_1}\right) \][/tex]

where:

-[tex]\( V_1 \) and \( V_2 \)[/tex] are the initial and final volumes.

Given values:

- [tex]\( V_1 = 3.6 \) L[/tex]

- [tex]\( V_2 \)[/tex] can be calculated using the ideal gas law:

[tex]\( V_2 = \frac{nRT_2}{P_2} \),[/tex] where \( n \) is the number of moles, [tex]\( R \)[/tex] is the gas constant,[tex]\( T_2 \)[/tex] is the final temperature in Kelvin, and [tex]\( P_2 \)[/tex] is the final pressure.

c. Determine the exergy of the air at the initial and the final states: Exergy [tex](\( X \))[/tex] is given by the equation:

[tex]\[ X = h - h_0 - T_0(s - s_0) \][/tex]

where:

- [tex]\( h \)[/tex] is the enthalpy per unit mass,

-[tex]\( h_0 \)[/tex] is the enthalpy at a reference state,

- [tex]\( T_0 \)[/tex] is the temperature at the reference state,

- [tex]\( s \)[/tex]  is the entropy per unit mass,

- [tex]\( s_0 \)[/tex] is the entropy at the reference state.

Given values:

-[tex]\( T_0 = 15 + 273.15 \)[/tex]K (temperature of the surroundings)

- [tex]\( P_0 = 112 \) kPa[/tex] (pressure of the surroundings)

We'll need to calculate [tex]\( h \), \( h_0 \), \( s \), and \( s_0 \)[/tex] for both initial and final states.

d. Determine the minimum work that must be supplied to accomplish this compression process: The minimum work required [tex](\( W_{\text{min}} \))[/tex]for an isentropic process can be calculated using the following equation:

[tex]\[ W_{\text{min}} = h_1 - h_2 \][/tex]

where:

-[tex]\( h_1 \)[/tex] is the enthalpy at the initial state,

- \( h_2 \) is the enthalpy at the final state.

e. Determine the second law efficiency of this process: The second law efficiency[tex](\( \eta \))[/tex] is given by the ratio of the actual work done[tex](\( W_{\text{actual}} \)) to the minimum work (\( W_{\text{min}} \)[/tex]):

[tex]\[ \eta = \frac{W_{\text{actual}}}{W_{\text{min}}} \][/tex]

Given values:

- [tex]\( W_{\text{actual}} = 1.9 \) kJ[/tex]

Now, let's go step by step and calculate each part of the problem.

a. Entropy Change per Unit Mass[tex](\( \Delta s = s_2 - s_0 \))[/tex]:

Using the given specific heats [tex]\( c_p \), \( R \)[/tex], temperatures [tex]\( T_1 \), \( T_2 \)[/tex], pressures [tex]\( P_1 \), and \( P_2 \)[/tex]:

[tex]\[ \Delta s = c_p \ln\left(\frac{T_2}{T_1}\right) - R \ln\left(\frac{P_2}{P_1}\right) \][/tex]

Substitute the values:

[tex]\[ \Delta s = 1.009 \ln\left(\frac{231 + 273.15}{28 + 273.15}\right) - 0.287 \ln\left(\frac{830}{137}\right) \][/tex]

[tex]\[ \Delta s \approx 1.009 \ln(1.842) - 0.287 \ln(6.0657) \][/tex]

[tex]\[ \Delta s \approx 0.6087 \, \text{kJ/kg·K} \][/tex]

b. Volume Change per Unit Mass [tex](\( \Delta v = v_2 - v_0 \))[/tex]:

First, calculate [tex]\( V_2 \)[/tex] using the ideal gas law:

[tex]\[ V_2 = \frac{nRT_2}{P_2} \][/tex]

where [tex]\( n \)[/tex] is the number of moles of air, which can be calculated using the initial conditions:

[tex]\[ n = \frac{P_1V_1}{RT_1} \][/tex]

Substitute the values and calculate[tex]\( V_2 \)[/tex]:

[tex]\[ n = \frac{137 \times 3.6}{0.287 \times (28 + 273.15)} \][/tex]

[tex]\[ n \approx 1.932 \, \text{kg} \][/tex]

[tex]\[ V_2 = \frac{1.932 \times 0.287 \times (231 + 273.15)}{830} \][/tex]

[tex]\[ V_2 \approx 1.476 \, \text{L/kg} \][/tex]

Now, calculate [tex]\( \Delta v \)[/tex] :

[tex]\[ \Delta v = R \ln\left(\frac{V_2}{V_1}\right) \][/tex]

[tex]\[ \Delta v \approx 0.287 \ln\left(\frac{1.476}{3.6}\right) \][/tex]

[tex]\[ \Delta v \approx -0.5305 \, \text{m}^3/\text{kg} \][/tex]

The negative sign indicates compression.

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Energy given off by the system during dissolution equals the energy absorbed by the surroundings. Therefore, option (A) is correct.

The law of energy conservation states that energy can only be transmitted or changed. This equation says that the energy produced by the system during exothermic dissolution, where a material dissolves while generating heat, is equal to the energy received by the solvent and container.

Solute molecules spread and interact with the solvent, forming or breaking bonds and releasing heat. The environment absorbs this heat, keeping energy balance. The law of energy conservation emphasises that energy changes in a system must be counterbalanced by energy changes in the surrounding environment, reinforcing the idea that energy is conserved during exothermic dissolution. Therefore, option (A) is correct.

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The law of conservation of energy states that the energy in a system cannot be created or destroyed, only changed in form. In exothermic dissolution processes, the energy given off by the system as heat is equal to the energy absorbed by the surroundings.

According to the law of conservation of energy, energy can neither be created nor destroyed, only changed in form during a chemical or physical change. In the case of exothermic dissolution processes, energy is given off by the system as heat, and this energy is equal to the energy absorbed by the surroundings. This means that the energy released during dissolution is the same as the energy gained by the surroundings.

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Answer:

Concentration of water at equilibrium is 0.1177 M.    

Explanation:

Balanced equation: [tex]CH_{4}(g)+H_{2}O(g)\rightleftharpoons CO(g)+3H_{2}(g)[/tex]

Equilibrium concentration of [tex]CH_{4}[/tex], [[tex]CH_{4}[/tex]] = [tex]\frac{0.231}{0.669}[/tex] M = 0.345 M

Equilibrium concentration of CO, [CO] = [tex]\frac{0.276}{0.669}[/tex] M = 0.413 M

Equilibrium concentration of [tex]H_{2}[/tex], [[tex]H_{2}[/tex]] = [tex]\frac{0.207}{0.669}[/tex] M = 0.309 M

Equilibrium constant for the given reaction in terms of concentration, [tex]K_{c}[/tex] is expressed as:           [tex]K_{c}=\frac{[CO][H_{2}]^{3}}{[CH_{4}][H_{2}O]}[/tex]

                          [tex]\Rightarrow [H_{2}O]=\frac{[CO][H_{2}]^{3}}{[CH_{4}].K_{c}}=\frac{(0.413)\times (0.309)^{3}}{(0.345)\times (0.30)}= 0.1177[/tex]

Hence, concentration of water at equilibrium is 0.1177 M                          

I think the answer is B...

I am not sure

Answer:

B

Explanation:

Hurricanes are very powerful, circular storms that begin over warm water. These storms have heavy rains, very high winds, and low atmospheric pressures. They are fueled by a strong cycle of warmer, moister air flowing upward from near the ocean's surface and being replaced by cooler, drier air from the surrounding area. This cycle gets faster and stronger as it is fed by the ocean's heat and water evaporating from the ocean's surface.

So, the first step in hurricane formation occurs when warm ocean water evaporates and then condenses, forming a low pressure area below.

Answer:

Laura can look for a transparent and  translucent liquid and hence determine which beaker has water and which has solution

Explanation:

Pure water is a compound that is transparent in color. However, a solution is a liquid mixture comprising of a solvent or a solute. The atoms of solute occupy space between the atoms of solvent and hence are said to dissolve in it. Water can be a solvent.  

Thus, if the beaker has a transparent liquid in it, then it would be pure water while a beaker having a translucent liquid, then it would be a solution  

Final answer:

Laura can differentiate pure water from solutions by using a conductivity test, indicators like pH paper or red cabbage water, measuring boiling and freezing points, or measuring the refractive index with a refractometer.

Explanation:

Laura can determine which beakers contain pure water and which contain solutions by conducting a series of tests that rely on the physical and chemical properties of the substances. Here are potential methods for differentiating between pure water and solutions:

Conducting a conductivity test, as pure water is a poor conductor of electricity while solutions with ions will conduct electricity.

Using indicators such as pH paper or red cabbage water, as solutions might be acidic or basic, changing the color of the indicator while pure water will not.

Examining the boiling and freezing points, as solutions have different boiling and freezing points compared to pure water.

Employing a refractometer or similar devices to measure the refractive index, which would differ between pure water and a solution.

To elaborate, a conductivity test can be set up by inserting electrodes into each beaker and connecting these to a circuit with a bulb or a conductivity meter. A color change when using red cabbage water as an indicator would signify the presence of an acidic or basic solution, since red cabbage juice changes color at different pH levels. Observing the boiling and freezing points would require heating or cooling the liquid and taking note of the temperature at which the change of state occurs. Pure water has specific boiling and freezing points (100°C and 0°C at standard atmospheric pressure), and deviations from these numbers would indicate a solution. Lastly, a refractometer could be used to compare the refraction of light through the liquids against known values for pure substances, revealing which beakers contain pure water and which contain solutions.

The three things that should be mentioned are Helium in Balloons, Lithium in Batteries, Beryllium in Emeralds, and Boron in Sports equipment.

Elements or rather compounds seem to be natural pure chemical substances.

The distinction here between element as well as a compound is whether an element is a compound consisting of the same type of atoms as a compound.

Whereas a compound is made up of various elements in specific proportions. Elements include iron, copper, hydrogen, and oxygen.

Metals are on the left side of the staircase, metalloids are on the right, and nonmetals are on the right.

An atom is a component of an element. An element is made up of only one type of atom.

Atoms are further subdivided into subatomic particles known as electrons, protons, and neutrons. Chemical reactions allow elements to combine to form molecules.

Thus, the three examples are helium, lithium, and boron.

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Answer:

4.83% of acetic acid in the vinegar

Explanation:

Answer:

0.382 g

Explanation:

Let's consider the reduction of gallium (III) to gallium that occurs in the electrolysis.

Ga³⁺ + 3 e⁻ → Ga

We can establish the following relations:

We will use this that to determine the mass of gallium deposited from a Ga(III) solution using a current of 0.880 A that flows for 30.0 min

[tex]30.0min \times \frac{60s}{1min} \times \frac{0.880c}{s} \times \frac{1mole^{-} }{96,468c} \times \frac{1molGa}{3 mole^{-}} \times \frac{69.72g}{1molGa} = 0.382 g[/tex]

Answer:

It opens the can for him

Explanation:

Answer:

Takes the pain off the mans hand.

Explanation:

Saw that you didn't like europa2433, i just kinda wanted to agree he reports to much.

Answer:

%error = 0.32%

Explanation:

Let's answer both questions, by parts.

1. Percentage error:

In this case, I do not have the video, but I do have the reported melting point of naphtalene which is 80.26 °C.

The expression to calculate the percentage error is the following:

%Error = absolute error / actual percentage. (1)

And the absolute error is:

Abs error = actual value - experimental value  (2)

But the experimental value is a range, so we just have to get a average of that:

Exp value = 77 + 83 / 2 = 80 °C

Now the absolute error:

Abs error = 80.26 - 80 = 0.26 °C

Finally the %error:

%error = (0.26 / 80.26) * 100

2. Meaning of melting point range and %error

The melting point range just means that the sample of naphtalene has impurities, and when a sample of any compound has impurities, melting point tends to be low. However, this decrease of temperature is a wider range. But usually a range of just 5° C means that compound has little traces of impurities but it can still be used for reactions.

The %error means that the impurities of the sample are really low, so the sample is practically pure with little traces of impurities.

Final answer:

The percent error for the melting point of naphthalene is calculated using the formula and considering the literature value of 80.2°C, yielding an approximate percent error of 0.25%. The broad melting range and low percent error suggest the sample is mostly pure with possible minor impurities.

Explanation:

The student's question is regarding the calculation of the percent error for the melting point of a sample of naphthalene and what the results suggest about the sample's purity.

Percent Error Calculation

To find the percent error, we use the formula:

Percent Error = (|Experimental Value - Literature Value| / Literature Value) x 100%

Assuming the literature value of naphthalene's melting point is approximately 80.2°C (the value will need to be verified as it can vary slightly in literature), we calculate percent error using the experimental value's mean (80°C, the midpoint of 77-83°C) as follows:

Percent Error = (|80°C - 80.2°C| / 80.2°C) x 100% = (0.2°C / 80.2°C) x 100% ≈ 0.25%

Suggestion About the Sample

The observed melting range of 77-83°C and the low percent error suggest that the sample is relatively pure but may contain minor impurities since a pure sample would have a narrower melting point range close to the literature value.

Answer:

It connects the two half‑reactions.

Explanation:

A salt bridge is a laboratory device used to connect the oxidation and reduction of half-cells of a galvanic cell. It prevents the cell from rapidly running its reaction to equilibrium.

Salt bridge or a porous plate connects the solutions of the half-cells that allow ions to pass from one solution to the other. This process balances the charges of the solutions and allows the reaction to continue.

The function of the salt bridge with respect to the electrochemical cell should be that it connected the two -half reactions.

It is the device that should be used in the laboratory for connecting the oxidation and the reduction of half-cells. It also prevents the cell from suddenly run from its reaction to the equilibrium.  Also, it connect the half cell solution where it probide the permission for ions from one solution to another solution. Moreover, there is balancing of the solutions charges due to this it permits the reaction for continuing it.

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The general formula for alkanes is CnH₂n+2. If it's containing 15 carbon, it contains 32 hydrogen atoms. The formula would be C₁₅H₃₂.

Alkenes are defined as either branched or unbranched hydrocarbons with a general formula of CnH2n with at least one carbon-carbon double bond (CC).

Alkenes are unsaturated hydrocarbons with carbon-carbon double bonds and have the chemical formula CnH2n. The molecular structure of this is the same as that of cycloalkanes.

The naming convention for alkenes is the same as that for alkanes, with the exception that the suffix is now -ene.

Substitute 15 for n.

The number of hydrogen atoms is 2×15+2=32.

The formula for an acyclic alkane with 15 carbon atoms is C₁₅H₃₂.

Therefore, CnH₂n+2 is the standard formula for alkanes. 32 hydrogen atoms are present if it has 15 carbon atoms. The equation would be  C₁₅H₃₂.

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